Sixteen common landform types

The floorboard of special landforms such as Fangshan, Qifeng, cliffs, caves and stone pillars composed of extremely thick red sandstone and conglomerate. A kind of rock landform. It is mainly developed in the horizontal or gently inclined red continental strata from Jurassic to Tertiary. Take Danxia Mountain in Renhua County, Guangdong Province, China as a typical example. It has the morphological characteristics of flat top, steep slope and slow foot. The development of Danxia landform began with Himalayan movement in Late Tertiary, which deformed some red beds and uplifted the basin. The red strata are eroded by flowing water, gravity and wind along vertical joints, forming deep ditches, residual peaks, stone walls, stone pillars, collapse cones, stone buds, caves, funnels, stalactites and other landforms. The main peaks are squares, forts, pagodas and monoclinic peaks. Danxia landform area is rich in strange peaks, magnificent scenery and rich in tourism resources, and some of them have become scenic spots, such as Danxia Mountain, Jinjiling Mountain and Wuyishan Mountain. It is the best area to study and restore the ancient geographical environment of the Red Basin.

2. Karst landform

The floorboard of the surface and underground forms formed by dissolving soluble rocks with water. Also known as karst landform. The action of water on soluble rocks is called karstification. It is dominated by dissolution, and also includes mechanical erosion processes such as running water erosion, latent erosion and collapse. This effect and its phenomenon are collectively called karst. Karst is the place name of carbonate plateau in Istra Peninsula in northwest Yugoslavia, and it is called Kras locally, which means the place where rocks are exposed. Modern karst research originated in this area, hence its name.

Karst landforms are distributed in soluble rock areas all over the world. There are three types of soluble rocks: ① carbonate rocks (limestone, dolomite, marl, etc. ). ② Sulfate rock (gypsum, anhydrite, mirabilite). (3) Halide rocks (potassium, sodium, magnesium salt rocks, etc. ). The total area is 5 1× 106 square kilometers, accounting for 10% of the total area of the earth. Karst landform develops from tropical zone to cold zone, and from mainland to island. Famous areas include China, Guangxi, Yunnan, Guizhou, northern Vietnam, Dunac Alps in Yugoslavia, Alps at the junction of Italy and Austria, French Central Plateau, Russian Urals, southern Australia, Kentucky and Indiana in the United States, Cuba and Jamaica. The karst landforms in China are widely distributed and cover a large area. It is mainly distributed in the exposed area of carbonate rocks, covering an area of about 9 1 ~ 1.3 million square kilometers. Among them, Guangxi, Guizhou and eastern Yunnan have the largest areas and are one of the largest karst areas in the world. Tibet and some northern areas are also distributed.

Karst can be divided into many different types. According to the exposure conditions, it can be divided into bare karst, covered karst and buried karst. According to climatic zones, it can be divided into tropical karst, subtropical karst, temperate karst, cold karst and arid karst. According to lithology, it can be divided into limestone karst, dolomite karst, gypsum karst and salt karst. In addition, there are different divisions according to altitude, development degree, hydrological characteristics and formation period. Phenomena similar to karst in form due to other differences are collectively called pseudo-karst, including clastic karst, loess and clay karst, hot lava karst and lava karst in volcanic rock area. They are not composed of soluble rocks, which are essentially different from karst.

Karst landforms are most developed in carbonate strata distribution areas. Rock outcrops and strange peaks abound in this area. The common karst landforms on the surface include karst positive landform such as stone bud, stone forest, peak forest and karst hills, and karst negative landforms such as karst gullies, sinkholes, blind valleys, dry valleys and karst depressions. Underground karst landforms include karst caves, underground rivers and underground lakes. As well as the karst landforms closely related to the surface and underground, such as shafts, bud caves and Tianshengqiao.

Karst research has important theoretical and practical significance. There are many unfavorable factors to be overcome and prevented in karst areas, and there are also many favorable factors to be developed and utilized. . Karst mineral springs and hot springs are rich in beneficial elements and gas, and various sedimentary minerals on karst caves and ancient karst surfaces have rich medical value. Ancient karst buried hill is a good oil and gas reservoir structure. The grotesque caves in karst areas, rivers with alternating light and dark, and clear karst springs are all good tourism resources.

3. Coastal topography

The general name of all kinds of landforms formed by tectonic movement, seawater dynamics, biological action and climate factors. The alternation of Quaternary Glacial Period and Interglacial Period caused the sea level to rise and fall, and the coast was constantly changing. 6000 ~ 7000 years ago, the sea level rose to the height equivalent to modern sea level, which constituted the basic outline of modern coast and formed various coastal landforms.

In the process of shaping coastal landforms, tectonic movement laid the foundation. On this basis, wave action, tidal action, biological action and climate factors have shaped many complex coastal shapes. Wave action is the most active dynamic factor in shaping coastal landforms. Offshore waves have great energy. According to theoretical calculation, the wave height is 1m, and the wave with a period of 8 seconds propagates 8× 106 joules per second on the coast stretching 1km. The coast is constantly eroded under the action of waves, and various marine erosion landforms are developed. Debris eroded by sea waves is carried by coastal currents and accumulates in areas with weak input wave energy, forming a variety of accumulation landforms. Tidal current is the main force of sediment transport. When the actual sediment concentration of tidal current is lower than its sediment carrying capacity, it can continue to scour the seabed; When the actual sediment concentration exceeds the sediment carrying capacity, there will be some sediment deposition. In tropical and subtropical waters, there can be coral reef coasts; Mangrove coast can be formed in bays and beaches where salt marsh plants are widely distributed. The reproduction and metabolism of organisms have certain decomposition and destruction effects on coastal rocks. In different climatic zones, with the difference of temperature, precipitation, evaporation and wind speed, the form and intensity of coastal weathering are different, which makes the coastal landform have certain zonality.

According to the basic characteristics of coastal landforms, it can be divided into two categories: coastal erosion landforms and coastal accumulation landform. Erosion landforms refer to various landforms formed by continuous erosion of rocky coasts by waves and tidal currents, mainly including sea caves, sea cliffs, sea platforms and sea pillars. Due to the different composition of coastal materials, the speed of erosion and the degree of landform development are also different. Accumulated landforms are all kinds of landforms formed by the deposition of nearshore materials carried by waves, tidal currents and winds. According to the relationship between the shape of the accumulation body and the coast and its causes, it can be divided into adjacent landform, free landform, closed landform, surrounding landform and coastal landform. According to the material composition and morphology of the coast, it can be divided into sandy coast, muddy coast, delta coast and biological coast.

The world coastline is about 440,000 kilometers long. China's coastline is1.8000 km long, and the island coastline is1.4000 km long. The coastal zone is rich in natural resources, such as minerals, biology, energy and land. This is an important field of human activities. There are industrial cities and seaports everywhere. It is not only a national defense outpost, but also a hub of land and sea transportation and an important base for economic development. It is of great significance to study the coastal landform, master the evolution process of seahorse seal beach and predict the changing trend of the coast for the rational development and utilization of natural resources such as port construction, reclamation, aquaculture, tourism and coastal energy.

4. Submarine landform

The general term for the surface morphology of the solid earth covered by seawater. There are towering seamounts, undulating seamounts, continuous seamounts, deep trenches and open abyssal plains on the seabed. The mid-ocean ridge runs through the center of the ocean, stretching for 80,000 kilometers and several hundred to several Qian Qian meters wide, with a total area comparable to the global land. The deepest part of the ocean is11034m, which is located in the Mariana Trench in the Pacific Ocean, exceeding the altitude of Mount Everest (8846.27m), the highest peak on land. The slope of the deep-sea plain is less than one thousandth, and the flatness exceeds that of the continental plain. The whole seabed can be divided into three basic geomorphic units: continental margin, ocean basin and mid-ocean ridge, and several sub-seabed geomorphic units. (1) the continental margin. It is a transitional zone between the mainland and the ocean floor, accounting for about 22% of the total ocean area. Usually divided into Atlantic continental margin (also known as passive continental margin) and Pacific continental margin (also known as active continental margin). The former consists of three units: continental shelf, continental slope and continental uplift. The terrain is broad and gentle, and it is more common in the peripheral areas of the Atlantic Ocean, Indian Ocean, Arctic Ocean and Southern Ocean. The latter has a narrow continental shelf, steep continental slope and undeveloped continental uplift, but it is replaced by a trench, which can be divided into trench-island arc-marginal basin series and the Andean continental margin near the continental margin, mainly distributed in the Pacific Rim and also found in the northeastern margin of the Indian Ocean. ② Ocean basin. Located between the mid-ocean ridge and the continental margin, one side is connected with the gentle slope of the mid-ocean ridge, and the other side is adjacent to the continental ridge or trench, accounting for 45% of the total ocean area. The sea basin is divided by normal topography such as ocean ridges, forming a number of submarine depressions with a water depth of about 4000 ~ 5000 meters, which are called sea basins. A long submarine depression with large width and gentle slope is called a trough. Deep-sea plains and deep-sea hills are developed at the bottom of the basin. A long submarine highland is called a seamount or ridge, a wide and gentle submarine highland is called a seamount, and a flat-topped submarine highland with steep slopes around it is called a sea platform. ③ Mid-ocean ridge. The mountains in the longest and widest global ocean on earth account for 33% of the total ocean area. The mid-ocean ridge is divided into ridge top area and ridge wing area. The ridge top region consists of several rows of almost parallel ridges and valleys alternately. The ridge top is a new marine crust, with extremely thin or missing overlying sediments and very rugged terrain. With the increase of ocean crust age and the thickening of sediments, the height difference between ridges and valleys gradually decreases, some valleys can be filled with sediments into steps, and relatively flat terrain can appear on the wings far from the ridge top.

Submarine landforms, like terrestrial landforms, are the result of the combined action of internal and external forces. Submarine topography is usually the direct product of internal forces, which is closely related to submarine expansion and plate tectonic activities. The mid-ocean ridge axis is the center of submarine expansion. The deep sea floor lacks the compression and folding mountain system on land, and the formation of seamounts and seamounts is mostly related to volcanoes and fault blocks. External forces also play a role in shaping the seabed topography. Strong sedimentation can transform the original rugged volcano and tectonic terrain and form a deep-sea plain. Submarine canyon is the most spectacular manifestation of turbidity current erosion, but in the process of shaping submarine topography, except for continental margin, erosion is far less important than land. Waves, tides and currents have a profound influence on the topography of coastal and shallow sea areas.

5. Aeolian landform

Surface morphology formed by wind accumulation. Under the conditions of arid and semi-arid climate and abundant sources of sandstorm, it was carried by the wind and accumulated.

The provenance of aeolian landforms mostly comes from ancient river alluvium; Modern river alluvium; Alluvial-lacustrine deposit; Alluvium-alluvium; Ice water deposits; Residual slope deposits after weathering of bedrock. There are many factors affecting the development of aeolian landform, mainly the structure of sand-laden airflow, the direction of wind movement and sediment concentration. Such as the types of wind, there are single wind direction, double wind direction and multiple wind directions; The magnitude of wind speed and the synthetic direction of sandstorm; Degree of ground fluctuation; Thickness and quantity of ground members; Ground humidity and vegetation distribution, etc.

The basic type of aeolian landform is sand dunes. The main types of dunes are crescent dunes, crescent dune chains, compound crescent dunes and dune chains, parabolic dunes, longitudinal dunes, crescent dunes, compound longitudinal dunes, pyramid dunes, honeycomb dunes and sandy land.

6. Wind erosion landform

Surface morphology formed by wind erosion and surface material wear. The main types of wind erosion landforms are: ① wind erosion caves. Small round or irregular oval caves and pits formed by wind erosion on steep windward rock walls. Large caves are called wind erosion pits. ② Wind-eroded mushrooms. Mushroom-shaped rock mass formed by wind erosion of isolated protruding rocks, also known as stone mushroom and wind mushroom. ③ Ya Dan terrain. In the accumulation areas of rivers and lakes similar to Xiangtu, there are alternate landforms of wind erosion hills and wind erosion depressions. Ya Dan is Uighur in China, which means steep mound. It is named after the most typical Ya Dan area located in the lower reaches of Peacock River in Xinjiang, China. Its development process is that sand-laden airflow erodes the ground and wind erosion grooves appear on the ground. The wear developed further, and the groove expanded into a wind erosion depression; The ground between depressions rises relatively and becomes a wind erosion mound. (4) Wind erosion castle. Castle-like hills formed by wind erosion of horizontal rock layers are also called windy cities. It is common in strata with different lithology (such as interbedded sandstone and mudstone). There are many windy cities in the Tertiary strata in Shisanjianfang area in eastern Xinjiang, China and south of Sanbao and Hami. ⑤ Wind erosion. Ridge-shaped slender shape formed by wind erosion in soft and hard interbedded rocks. Generally developed in mudstone, siltstone and sandstone areas. ⑥ Wind erosion valley. A valley formed by wind erosion widening and deepening gullies. The valley has no definite shape. The wind erosion valley has been expanding and shrinking, and finally only some isolated hills are left, that is, wind erosion residual hills. ⑦ Wind erosion depression. Elliptical rows of depressions formed by wind erosion on the ground composed of loose materials. Deep wind-eroded depressions, if groundwater overflows or stores rainwater in the future, can become lakes in arid areas, such as Wulan Lake in Hulunbeier Sandy Land of China.

7. River landform

The general name of various erosion and accumulation landforms formed by rivers through erosion, transportation and accumulation on the earth's surface.

River action is the most frequent and active geomorphic action on the earth's surface, which runs through the whole process of river geomorphology. No matter what kind of river has erosion, transportation and accumulation, and forms different types of landforms.

Rivers can generally be divided into three parts: upstream, middle and downstream. From upstream to downstream, the erosion ability is weakened and the accumulation effect is gradually enhanced. There are different types of rivers according to their plane morphology, river pattern dynamics and distribution areas. According to the plane shape, it can be divided into straight type, curved type, branched type and wandering type; According to the river regime, it can be divided into two types: relatively stable type and wandering type. The river landforms in mountainous areas and plains have different laws and characteristics of development and evolution. Mountain valleys are mostly V-shaped or U-shaped, with large longitudinal slope, and there is no obvious boundary between valley bottom and valley slope. Bedrocks are often exposed along the banks and bottoms of rivers, mostly straight rivers. There are many thick alluvium in the valley of plain rivers, and there are complete broad and flat flood plains. The cross section of the valley is wide U-shaped or W-shaped, and the longitudinal section of the river bed is relatively flat, which is often a smooth curve with a small slope, and most of them are curved, branched and winding rivers.

Landforms include erosion and accumulation landforms. The former includes erosion river bed, erosion terrace, valley and valley slope. The latter includes: flood plain, accumulation terrace, alluvial plain, estuary delta and so on. River terrace is an important landform type in river landform, which can be divided into erosion terrace, accumulation terrace (overlapping terrace and folding terrace), pedestal terrace and buried terrace. The study of river terrace types and valley structure can analyze the past of river landforms, understand the present and predict the future development of rivers.

8. Glacier topography

Surface morphology formed by glacial erosion and accumulation. 1 1% of the earth's land surface is covered by modern glaciers, mainly distributed in polar regions, middle and low latitudes, mountains and plateaus. During the Quaternary Ice Age, the continental ice sheets in Europe, Asia and North America were continuously distributed and once spread to a wider area than today, leaving a large number of glacial remains on the surface.

Glacier is a quasi-plastic body, and its movement includes two parts: internal movement and bottom sliding, which is the driving force for erosion, transportation, accumulation and shaping various glacier landforms. However, it is not the only driving force to shape the glacier landform, but it works with freezing, snow erosion, avalanches, running water and other forces to form the landscape of the glacier area.

Glacial landforms can be divided into glacial erosion landforms and glacial accumulation landforms. Glacier erosion landform is that there are different amounts of clastic rocks in glacier ice. During the movement, the rocks at the valley bottom and slope are crushed, abraded and pulled out, forming a series of glacial erosion landforms such as glacier scratches, polished surfaces, sheep back, ice bucket, tinder, valleys, fjords and rock basins. Glacier accumulation landform is the landform formed by moraine accumulation during or after glacier movement, such as terminal moraine ridge, lateral moraine ridge, moraine mound, gully moraine, drum hill, serpentine mound, glacial gravel mound, glacial plain and glacial terrace.

9. Periglacial landform

Surface morphology formed by freezing weathering and freezing and thawing. Periphery originally refers to the marginal area of glaciers, but now it generally refers to the cold climate area without glacier cover, which is equivalent to the frozen soil distribution area, and some seasonal frozen soil areas also develop periglacial landforms. So the periglacial landform is also called frozen soil landform. A series of freezing and melting processes on the surface due to annual, daily and phase changes of temperature are called periglacial action. There are mainly frost heaving, hot melt creep, hot melt, snow erosion and wind power. The main landform types formed by periglacial action are: rock sea, rock river, polygonal earth-rock ring, ice mound and ice cone, hot melt landform and snow erosion depression.

Glacier landform combination has certain distribution law, from the center of glacier to the periphery, from erosion landform to accumulation landform. According to the altitude, mountain glacier landforms can be divided into: above the snow line, there are ice buckets, tinder and ridge glacier marginal action zones; Below the snow line to the final moraine ridge is a glacial erosion-accumulation landform interlaced zone; The lowest part is terminal moraine, glacial valley and ice plain.

10, lake landform

Various surface forms formed by lake water (including lake wave erosion, transportation and accumulation). Lake wave is a phenomenon that wind force causes water point vibration on the lake. Lake wave can transform the material carried by the river, erode the bank slope of the lake and form the bank slope landform of the lake on the shore. Lake waves hit the shore, and the generated waves beat the shore, forming a lake erosion landform dominated by erosion, such as lake erosion cliffs, lake erosion caves, lake erosion terraces and so on. Lake landforms include: lake terraces, lake plains, lake sandbars, etc. The substances carried by rivers entering the lake can form a lakeside delta in the hukou area. Due to wind, air pressure, landslide, landslide, earthquake and other reasons, the water level of the lake can change rhythmically around a certain position, thus forming underwater collapse, landslide, muddy valley, muddy fan and so on. When the lake is continuously filled and silted up, the lake becomes shallow and gradually evolves into a swamp.

1 1, structural landform

Terrain formed by geological structure. Including geological structures and new structures formed since Neogene. The main types of tectonic landforms are plate tectonic landforms, fault tectonic landforms, fold tectonic landforms, volcanic tectonic landforms, lava tectonic landforms and rock tectonic landforms. Geomorphology formed by various structures eroded by external forces during geological period. Such as anticline mountain and anticlinal valley; Syncline mountain and syncline valley; Fault cliff, fault line cliff, etc. The remains such as folds and faults formed by neotectonic movement are called neotectonic movement. Neotectonic movement can be divided into vertical movement and horizontal movement. Landforms formed by vertical crustal movement, such as rising mountains, hills and platforms; Descending plains and basins; Terraces that rise intermittently, etc. Large-scale horizontal crustal movement makes the crust compress or stretch, which can form large-scale continental folded mountain plateau, continental rift and fault basin; Island arcs, trenches and continental waves on the continental margin; Landforms such as ridges and volcanoes on the seabed.

12, thermal karst landform, a hot melt landform

Terrain formed by thermal melting of underground ice. Also known as thermal karst landform. Hot melt is the process of soil shrinking and sinking after the ice in frozen soil melts.

Hot melt landforms can be divided into two categories:

(1) Hot melt settlement mainly occurs on the flat land, forming settlement funnels, depressions and settlement basins, and becoming a thawing lake after accumulating water. Most of them are developed in plain or plateau areas.

(2) Hot melt slump, mostly developed on gentle slopes < 16. There are crescent-shaped, long-shaped, armchair-shaped, tree-shaped and other planar shapes. There is an obvious seasonal activity cycle. The hot melt collapse in the northern Daxing 'anling Mountains in China and Qilian Mountains in Shandong Province starts every spring, reaches its peak in summer and gradually stops in autumn.

13, artificial landform

The general name of geomorphic bodies shaped by human activities on the earth's surface. Also known as artificial landforms. The influence of human beings on the earth's surface topography is comprehensive, both constructive and destructive; There are not only direct changes in geomorphic processes and types, but also indirect changes in geomorphology through various social, production and scientific practice activities of human beings. With the development of human society and economy, the influence on the earth's surface landform is increasing day by day, and its feedback and influence on human living environment is also more frequent, which has attracted the attention of all countries in the world. For example, due to the industrial revolution and the high density of urban population, the greenhouse effect, global warming and sea level rise have been enhanced, endangering human production and life.

Man-made landforms can be divided into four aspects:

(1) Human activities directly transform the landform formed on the surface. It can be constructive, such as digging canals to divert water, leveling slopes and repairing fields; It can also be destructive, such as man-made collapse and landslide caused by slope slag accumulation.

(2) Human beings use and transform land through agricultural production, and promote the formation of various (good and bad) landform systems in agricultural areas. For example, land reclamation causes serious soil erosion, and gardening can alleviate desertification.

③ By developing cities, human beings have established a new urban landscape system.

④ Human beings have changed the process and types of landforms through a large number of engineering and technical activities. For example, the construction of dams has changed the process of erosion, transportation and accumulation of rivers, and excessive exploitation of groundwater has caused land subsidence.

14, gravity landform

The surface morphology formed by the displacement of rock mass or soil mass on the slope under its own gravity. Because most of the materials moving by gravity on the slope appear in the form of blocks, this movement is also called block movement. According to the movement mode, it can be divided into three categories: caving, sliding and peristalsis.

The types of gravity landforms formed are:

① Collapse, which can be divided into different forms of collapse landforms formed by landslides, bank collapses and loose bodies.

② Landslide.

③ Crawling soil chips.

④ Soil slide can be divided into freeze-thaw soil slide and tropical soil slide. Sometimes, the debris flow in the valley is included in the gravity landform. In fact, it is a transitional landform type between gravity landform and flowing water landform.

Weathered and loose rocks and debris on the surface are the general names of various geomorphological phenomena mainly caused by the movement of blocks under the action of gravity. The process is divided into two categories: one is a sudden process, which often causes disasters; First of all, this is a slow and non-catastrophic process. Geomorphological phenomena are as follows: (1) The material on the upper hillside keeps moving, which makes the hillside retreat gradually; The nearby foothills accepted the accumulation of unclassified debris, which slowed down the slope; The shape of the whole hillside is constantly changing with the two. Gravity landforms are divided into erosion type and accumulation type, the former is mainly steep cliffs; The latter mainly includes rockfill piles, debris flow slopes (debris flow slopes), landslide steps, landslide bulges, debris flow fans, debris flow terraces, stone glaciers and so on. The reasons include natural factors and human factors. Natural factors refer to the loose weathered layers and weathered cracks of rocks caused by various weathering, the development degree and occurrence of rock structural planes and landforms, the infiltration of water activities reduces the strength and angle of repose of rock and soil, erosion, undercurrent and dissolution produce free surfaces, and increase the shear force and vibration of rock and soil. They change with the change of natural conditions in different places, so gravity landforms have certain regional characteristics. Man-made factors mean that various economic activities destroy the natural stability of slopes. Gravity landforms are everywhere, even under the sea. Because it has certain environmental effects, including sudden disaster landform process and surface sand fossilization, it has attracted people's attention. Because the occurrence of gravity landform has deformation time effect, it can be predicted. China successfully predicted Xintan landslide in Zigui County, Hubei Province.

15, Loess landform Loess landform

Topography developed in loess stratum. Loess is a quaternary continental yellow silt deposit, accounting for110 of the land area.

Typical loess landforms have the following characteristics:

The valley is vertical and horizontal, and the ground is broken. Gully density in China Loess Plateau is 3000 ~ 5000 m/km2, and the maximum value is 10000m/km2. The cutting depth of the valley is 50 ~ 100 m. The valley area accounts for 30% ~ 50% of the basin area, and some reach more than 60%. The ground slope > 15 accounts for about 60% ~ 70% of the loess area, and the slope < 10 does not exceed 10%.

② The erosion mode is unique and the process is rapid. Erosive forces include water, wind, gravity and human activities. The modes of action include surface erosion, gully erosion, undercurrent, debris flow, block movement, excavation and soil migration, among which undercurrent can cause "pseudo-karst" landforms such as sinkholes, blind ditches, Natural Bridge, soil columns and dished depressions. The erosion resistance of loess is extremely low, and the erosion rate is 1 ~ 5cm/ year, and the individual gully heads can reach 30 ~ 40m/ year, and even a rainstorm washes into an erosion gully hundreds of meters long. ③ The river basin has multi-level ground. The highest watershed in each basin is the first level; Reduce 60 ~ 80 meters to the second level; Then lower 40 ~ 60 meters to the third level. Generally, the yellow soil layer sequence on the surface of the first-class terrain is relatively complete; The upper layer of the secondary topographic surface stripped loess is thin, so it disappears; The third-grade terrain is mostly Malan loess accumulation. The second and third topographical planes respectively constitute the river valley, and the modern river valley is below the third topographical plane. The layered structure of loess landform in gully basin records the historical process of loess landform development.

Loess landform types mainly include:

① Between loess gullies. Including loess plateau, beam, headland, headland, flat land, flat land and so on. The loess plateau with a flat and broad top is called tableland. The long loess hills are beams. The dome-shaped loess hills separated by valleys are wool. The ancient valley (formed about 6.5438 million years ago) is a flat valley formed by loess, which is called loess cave. The flat land divided into valleys is called loess plateau. Broken scales are distributed in strips along the ditch.